In another thread, I recently made the point that our high level of technology has made natural selection almost powerless in our species. I would like to discuss this issue more fully, since I think it is a very interesting one.

My main point is that many traits that, in the wild, would've been removed from the gene pool are instead allowed to continue in our society because we have, through technology, found ways of allowing such people to survive. I'm not suggesting that we starting killing everyone with bad eyesight, but I do think that the lack of selective pressure upon our species has led to some very undesirable outcomes. For example, I believe that as a species we are getting a lot less intelligent.

This may continue to a point where we are completely unable to survive without our technology (some would say we have reached that point already) or it may come to a point when the proliferation of disadvantageous genes in our species drives us into extinction.

Does anyone have any thoughts on the matter?

Generally speaking, the more people talk about "being saved," the further away they actually are from true salvation.

It is a worrying concept for the long term but do we have any proof that human intelligence is on the decline?

Natural Selection does not prevent survival and procreation in people with low intelligence, so I would not have thought that people used to be more intelligent in the past.

Now that we live much longer and with universal free education I would have thought that there were more, not less, people of an average higher intelligence, although it begs the question - How do you measure intelligence?

You are right that natural selection does not prevent the survival and procreation of people with low intelligence, but it does make people with higher intelligence more likely to survive and procreate.

It's hard to measure intelligence as far as our whole species is concerned so I'm mainly working off of my own speculation. As far as education, it does hold the promise of producing greater intelligence. However, at least in my area, public education is going downhill fast. For example, one parish near where I grew up neglected to teach phonics and thus has a very high illiteracy rate. So if education is supposed to make us smarter, it's not working as well as we'd like it too.

Also, our culture in general seems to be tolerating increasingly ridiculous ideas. I'm sure we all remember the case of the woman who spilled coffee on herself and won a million dollars because no one told her it was hot. I could quote numerous cases of such failures of our legal system, but the main question is, do you really think this would've happened two hundred years ago? I don't think it did, but if you can show me a case to the contrary, I'll reconsider.

Lastly, working in the service industry, I come into contact with a lot of stupid people. I admit this might give me a biased perspective, but if it can in any way be considered a sampling of the population as a whole, it doesn't give me much faith in our species.

Regardless of whether or not this is happening, do you at least think it's possible that our level of technology can inadvertently lead to disadvantageous genes becoming more and more common in our species instead of being removed through natural selection?

Generally speaking, the more people talk about "being saved," the further away they actually are from true salvation.

"Regardless of whether or not this is happening, do you at least think it's possible that our level of technology can inadvertently lead to disadvantageous genes becoming more and more common in our species instead of being removed through natural selection?"

I suppose YES would be my answer though I don't think it would have any significant effect on the general level of intelligence. It will allow more genetic defects to survive and procreate but that is because we have learnt to partially correct these "Imperfections of Nature". In the future, with Genetic Manipulation we may be able to completely correct these imperfections and then the genetic pool will not only return to its previous level of purity but improve, beyond the level which Natural Selection can achieve by itself. (Hence my other topic "Imperfect Man").

So, I do not think that your concern will become a problem. I think that Man will be able to improve things. (There may be a few errors or disasters on the way, but in a learning situation, that is the price that we pay).

There is one word of caution that I must add concerning genetic manipulation. It has nothing to do with any errors which may occur as we learn to control the process, for Nature (working by chance alone) makes millions of errors every day which are calmly discarded by Natural Selection without a grumble from anybody. The concern that I am talking about is a theoretical one. If genetic manipulation (using intelligence) were to be carried to the extreme by doing away with all variation in the genetic pool, then Natural Selection would have been deprived of the variations that it needs when environmental changes occur. That of course could lead to the sudden extinction of Homo Sapiens rather than to the evolution of Homo Sapiens into a new species.

But if genetic manipulation is used for the correction of unpleasant diseases, then I cannot see any major concerns.

You make a good point; it might be helpful to treat various genetic diseases that currently have no cure. However, for less serious but still "undesirable" traits, such as bad eyesight, it might be safer to stick with laser correction surgery and eyeglasses.

Generally speaking, the more people talk about "being saved," the further away they actually are from true salvation.

Cystics Fibrosis is not a pleasant disease, yet it still has a high prevalence in the caucasian population. Why? Heterozygous individuals show resistance to typhoid.

Is it so wise to use genetic engineering to eradicate diseases? Sure we could correct the gene in those poor homozygous sufferers, but isnt it wise to keep a frequency of the faulty allele in the population?

Kotoreru says "but isnt it wise to keep a frequency of the faulty allele in the population?"

In principle Yes, I agree that you have to keep variations, including certain faults in the genetic pool. For individuals who suffer the awful condition of cytic fibrosis and their parents who care for them, I am sure that your worries would not concern them one iota. The disease is so awful compared with the slight risk of catching typhoid (for which there is treatment and prevention) that no one would prefer to keep the genetic disorder if given the choice.

I wonder if anyone has any thoughts on the other part of my question. Does anyone else think that humanity as a whole is gradually getting dumber? Not only is the absence of natural selection allowing poor-intelligence genes to spread freely throughout the population, but our technology has also made life so convenient that many of us don't exercise our brains nearly as much as we used to. Just look at how many children grow up in front of a tv screen these days.

Generally speaking, the more people talk about "being saved," the further away they actually are from true salvation.

But I thought that Natural Selection worked mainly on the capacity of an individual to reproduce better than another individual. Not exercising our brains because of technology won't remove intelligence from the gene pool, so long as we can procreate.

It is like suggesting that because we use cars, we shall lose our legs. So long as a car doesn't stop me from procreating, then legs will continue to be be inherited down the line.